The long term goals of this study are to understand germ cell specification during animal development, in particular, how embryonic germ cells remain totipotent while other cells adopt terminally differentiated fates. This research will focus on the germ cells of C. elegans, which arise through a stem-cell-like cleavage pattern in early embryogenesis. The experiments will address what role(s) cytoplasmic granules called P granules have in germ cell development. P granules are associated exclusively with germ cells, or germ cell precursors throughout the C. elegans life cycle; this work will focus on the role of P granules in the germ cells of the adult gonad. Previous studies have shown that P granules in embryonic cells appear to contain RNA, and this will be determined for P granules in adult gonads. Gonads contain several distinct classes of RNA; high resolution in situ hybridization studies will determine which class, if any, is associated with P granules. In parallel to these studies, mutants with defects in P granule morphology will be isolated. These mutants may also be defective in P granule function, and could provide valuable insight into what that function(s) might be.